Stator ring construction



Nov. 5,A 1957 B. H. sHlNN s'AToR RING coNsTRUctrIN Filed Deo. e, 1951 f5 ZZ yUnitearl States Patent 2,812,158 s'TAToR RING CONSTRUCTION wBlyton H. Shinn, Rockville, Conn., assigner to United Aircraft Corporation, East Hartford, Conn., a corporation of Delaware Application December 6, 1951, Serial No. 260,225 11 Claims. (Cl. 253-48) j This invention relates to stator rings and particularly to a' simplified arrangement for holding the stator vanes in position in axial flow compressors and the like.

Axial flow compressors are made up of spaced rows of stator vanes alternating with rows of moving blades with yalso in many compressors inlet guide vanes and exi-t 'guide vanes for changing the direction lof ow of the air through vthe compressor. The stationary vanes extend .between inner and outer supporting rings and are generally secured mechanically individually to either or both tcntion of the vanes by a band or hoop which surrounds they vanes and engages with the outer ends thereof.

In many instances two rows of stationary vanes are `located in closely spaced axial relation as, for example,

v the last stage of' stator vanes and the exit guide vanes.

One feature of the invention is the retention of both rows of vanes in position by a means which extends around l, and engages with both rows of vanes and urges the rows of vanes apart axially and also urges both rows of vanes y `radially inward to retain the assembly in operative position.r

v Another feature is the arrangement of the stator ring to provide a measure of axial ilexibility between inner and outer shroud rings. For the last stage stator vanes, or the exit guide vanes, the inner and outer supporting .ringsvmay both be secured to fixed portions of the exit diffuser.y Considerable axial tolerance may accumulate during assembly between the fixed flanges and the cooperating parts on the inner and outer shroud rings. lln accordance with this feature of the invention the stator assembly may deflect and allow a measure of axial movement between inner and outer shrouds to allow proper tit with the diffuser flanges without developing critical stresses in the parts.

'Other objects andv advantages will be apparent from the specifica-tion and claims, `and from the accompanying drawings which illustrate an embodiment of the invention. Fig. l is a fragmentary longitudinal sectional view through the last compressor stage of a multistage compressor.

Fig. -2 is a fragmentary sectional view on ya larger scale showing the band which holds the vanes in position.

Fig. 3 is a `view similar to Fig. 1 showing a modification'for a single rov/ of vanes.

The' invention is shown in connection with a multistage -'axial iiow compressor having spaced rows 2 and 4 of stationary stator vanes alternating with spaced rows 6 'and Bof compressor' blades carried by the rotor 10. The

stator vanes 2 and 4 are positioned to change the direction of the ilow of air through the compressor for each successive stage, each stage being made up of a row of blades and the adjacent row of stator vanes. In the arrangement lshown there is a row of exit guide vanes 12 closely adjacent to the last row 4 of stator vanes.'

The air from the last row 4 of stator vanes and the row 12 of exit guide vanes is directed into a diffuser 14 defined by an inner wall 16 and an outer wall 18 connected together and held in predetermined relation to each other by radially extending struts 20. The outer wall 18 has a forwardly extending substantially cylindrical portion 22 ysecured as by bolts 24 to the compressor casing 26. The inner wall 16 of the diifuser has bolted thereto an inner vane supporting ring 28 and also sealing rings 30. A cooperating outer vane supporting ring 32 is positioned within the cylindrical portion 22 and engages at one end with a shoulder 34 on the wall 18. At its upstream end the ring 32 has a projecting flange 35 fitting between the casing 26 and the portion 22 of the outer wall. The ring 32 also has, at its upstream end, a tongue 36 engaging in a groove 38 provided by the box shroud 40 for the row 2 of stator vanes. This box shroud is described and claimed in the copending application of Hasbrouck and Shinn, Serial No. 212,974, now Patent No. 2,749,026, and is not a feature of this invention.

In accordance withy the present invention the vanes making up the row 4 of stator vanes have their inner ends provided with tongues 42 which project into correspondingly shaped openings 44 in the inner ring 28. These Y tongues prevent axial movement of the vanes, and the `shoulder 46 at the junction of thetongue with the vane functions as a stop to limit inward radial movement of the vane. The outer end of each vane is received in an opening 4S in the outer ring 32. Each opening 48 co1'- responds almost exactly to the shape of the vane leaving clearance enough for the insertion of theI vane through the opening. The outer ends of the vanes project beyond the ring 32 as best shown in Fig. 2. l

The vanes making up the row 12 of exit guide vanes are similarly arranged, each vane having a tongue 50 at its inner end engaging in an opening 52 in the -inner ring 28. The outer ring 32 has a row of openings 54 which receive the exitY guide vanes and the outer end' of each vane projects beyond the outer ring as best lshown in Fig. 2.

To hold the rows 4 and 12 of vanes in position these rows are surrounded by a band 56 which extends completely around in the form of a hoop and may haveits ends secured together as by a welded connection 58, Fig. l. This band is stressed prior Ito the attachment of its ends so that the band applies a radially inward pressure on the rows of vanes at all' times. For additionally securing the vanes the adjacent outer corners of the vanes are cut off at a substantial angle to the axis of the vane as `at 60 and `62. These obliquely extending surfaces cooperate to form a notch and the band 56 is provided with a centrally positioned projecting rib 64 which iits in this notch thereby applying when the band is tightened a pressure tending to move the outer ends of the vanes in the two rows axially apart in addition to the radial pressure applied by the band. The dimensions of the rib 64 in the Vband are preferably yso selected that the sole contact be-V The attachment of the ends ofthe band 56 may` beV a weldment as above described or it may be a mechanical attachment if desired. In any event the band is stressedY high enough in being applied so that there will be a substantial circumferential stress in the band to assur/e an adequate pressure to retain all of the vanes in both rows in position.

The same arrangement may be used in holding a single `row of vanes in position as shown, for example, in Fig. 3

where a row 68 of vanes extends between an inner supporting ring 70 and an outer supporting ring 72. The inner end of each vane has a projecting tongue 74 engaging in an opening 76 in the inner ring 70. The outer ring 72 has openings 78 which receive the vane and each vane projects beyond the outer ring as shown. The outer ring 72 has a projecting rib 80 spaced from the row of vanes and a band 82 having an inwardly projecting rib 84 is positioned between the rib 8l) and the obliquely extending surfaces 86 on the outer corners of the vanes. The band 82 thus functions to force the vanes radially inward and also forces them axially to hold the trailing edges of the vanes tightly in the slots provided in the outer supporting ring. In this arrangement the projecting edge of the band which extends over the ends of the vanes may be bent inwardly as at 88 so that it will engage with the outer ends of the vanes and provide an additional radial pressure.

It is to be understood that the invention is not limited to the specific embodiment herein illustrated and described, but may be used in other ways without departure from its spirit as defined by thc following claims.

I claim:

1. A stator ring assembly for a compressor or the like including inner and outer concentric spaced rings and a row of stator vanes extending between said rings, said inner ring having means locating each individual vane against radial inward movement and against axial movement, said outer ring having openings through which the vanes extend with the outer ends of the vanes projecting outside of said outer ring, and a circumferentially stressed band surrounding and separate from the outer ring and engaging the outer end surfaces of the vanes of the row to hold them against'radial outward movement.

2. A stator ring assembly for a compressor or the like including inner and outer concentric spaced rings and a row of stator vanes extending between said rings, said inner ring having means locating each individual vane and limiting its radial inward movement, said outer ring having openings through vwhich the vanes extend, the vanes being of such a length that with the vanes in assembled relation and in engagement with the inner ring the outer ends of the vanes project outwardly beyond the outer ring, and a band separate from and extending around the ring of vanes and engaging with the outer ends of the vanes to hold them in position said band being stressed circumferentially and tightly engaging said vanes.

3. A stator ring assembly for a compressor or the like including inner and outer concentric spaced rings and a row of stator vanes extendingvbetween said rings, said inner ring having means locating each individual vane and limiting its radial inward movement, said outer ring having openings through which the vanes are inserted, the vanes being of such a length that when the vanes are in assembled relation and in engagement with the inner ring the outer ends of the vanes project outwardly beyond the outer ring, and a band separate from and surrounding the row of vanes and engaging with an outer corner of each vane for holding said vanes axially and radially to retain the` vanes securely in position.

4. A stator ring assembly for a compressor or the like including inner and outer concentric spaced rings and a row of stator vanes' extending between said rings, said .Y ring the outer ends of the vanes project outwardly beyond the outer ring, and a circumferentially stressed band surrounding the row of vanes and urging said vanes axially and radially to hold the vanes securely in position, the outer ends of each of said vanes having an angularly extending surface with which the band engages to provide axial and radial pressure on said vanes.

5. A stator ring assembly for a compressor or the like including inner and outer concentric spaced rings, means for supporting said rings in axially fixed relation with respect to each other, and a row of stator vanes extending between said rings, said inner` ring having means locating each individual vane and limiting its radial inward movement, said outer ring having openings through which the vanes are inserted, the vanes being of such a length that when the vanes are in assembled relation and in engagement with the inner ring the outer ends of the vanes project outwardly beyond the outer ring, and a circumferentially stressed band extending around the row of vanes and engaging with the outer ends of the vanes to hold them in position, the outer ends of each of said vanes having an angularly extending surface with which the band engages to provide axial and radial pressure on said vanes 6. A stator ring assembly for a compressor or the like including inner and outer concentric spaced rings, means for supporting said rings in axially xed relation with respect to each other7 and a row of stator vanes extending between said rings, said inner ring having means locating each individual vane and limiting its radial inward movement, said outer ring having openings through which the vanes project, the vanes being of such a length that when the vanes are assembled and in engagement with the inner ring the outer ends of the vanes project outwardly beyond the outer ring, the outer ends of each of the vanes having an angularly extending v surface, and a band surrounding said vanes and engaging with the angularly extending surfaces to hold the vanes radially against outward movement, said outer ring having a cooperating surface adjacent to and engaging said band laterally whereby the band also holds the row of vanes against axial movement toward said band.

7. A stator ring assembly for a compressor or the like including inner and outer concentric spaced rings, two rows of closely spaced stator vanes extending between said rings, said inner ring having means locating each vane of each row and supporting it in axial position as well as against radial inward movement, said outer ring having two axially spaced rows of openings in which the vanes are positioned with the outer ends of the vanes projecting outwardly beyond the outer ring, and means surrounding the rows of vanes and engaging with the outer ends of both rows of vanes thereof for holding said rows of vanes against radial outward movement.

8. A stator ring assembly for a compressor or the like including inner and outer concentric spaced rings, two

' rows of closely spaced stator vanes extending between said rings, said inner ring having means locating each vane of each row and supporting it in axial position as well as supporting it against radial inward movement, said outer ring having two axially spaced rows of openings in which the vanes are positioned with the outer ends of the vanes projecting outwardly beyond the outer ring, and a band surrounding said rows of vanes and engaging with the outer ends thereof for holding the vanes in the rows against radial outward movement and for holding the vanes in each row against axial movement toward the vanes in the other row.

9. A stator ring assembly for a compressor or the like including inner and outer concentric spaced rings, two rows of closely spaced stator vanes extending between said rings, said inner ring having means locating each vane of each row and supporting it in axial position as well as supporting ity against radial inward movement, said outer ring having two axially spaced rows of `openings in which the vanes are positioned with the outer ends of the vanes projecting outwardly beyond the outer ring, and a band surrounding said rows of vanes and engaging with the outer ends thereof for holding the vanes in the rows against radial outward movement and for holding the vanes in each row against axial movement toward the vanes in the other row, said rows of vanes having angularly extending surfaces at their outer ends with the angularly extending surfaces located on adjacent corners of the vanes in the two rows, said band engaging with said angularly extending surfaces.

10. A stator ring assembly fon a compressor or the like including inner and outer concentric spaced rings and a row of stator vanes extending between said rings, said inner ring having means locating each individual vane radially, and said outer ring having openings through which the vanes extend with the outer ends of the vanes projecting outside of said outer ring, and a band surrounding said row of vanes and separate from said outer ring, said band engaging with an outer corner of each vane for holding the set of vanes against axial movement toward said corner and against radial outward movement.

11. A stator ring assembly for a compressor or the like including inner and outer concentric spaced rings and a row of stator vanes extending between said rings, said inner ring having means locating each individual vane 2 radially, and said outer ring having openings through References Cited in the le of this patent UNITED STATES PATENTS 1,932,264 Dickinson Oct. 24, 1933 1,932,278 Lacey Oct. 24, 1933 2,110,679 Robinson Mar. 8, 1938 2,201,099 Roe May 14, 1940 2,264,877 Haigh Dec. 2, 1941 2,316,813 Schaper Apr. 20, 1943 2,445,661 Constant July 20, 1948 2,640,319 Wislicenus June 2, 1953 2,658,719 Johanson Nov. 10, 1953 FOREIGN PATENTS 326,973 Great Britain Mar. 27, 1930 548,649 Great Britain Oct. 19, 1942 

